Antibiotics containing borinic acid complexes and methods of use

ABSTRACT

The structure and preparation of antibiotics incorporating borinic acid complexes are disclosed, especially hydroxyquinoline, imidazole and picolinic acid derivatives, along with compositions of these antibiotics and methods of using the antibiotics and compositions as bactericidal and fungicidal agents as well as therapeutic agents for the treatment of diseases caused by bacteria and fungi.

This application is a continuation of U.S. application Ser. No. 10/867,465, filed 14 Jun. 2004, which is a continuation-in-part of U.S. application Ser. No. 10/740,304, filed 18 Dec. 2003 (non-abandoned), which claimed priority of U.S. Provisional Applications Ser. No. 60/434,375, filed 18 Dec. 2002, Ser. No. 60/436,095, filed 23 Dec. 2002, and Ser. No. 60/437,849, filed 3 Jan. 2003, the disclosures of all of which are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to the field of antibiotics and particularly antibacterial and antifungal compounds and uses thereof. Methods for preparing and using these antibiotics, and pharmaceutical compositions thereof, are also provided.

BACKGROUND OF THE INVENTION

One hallmark of the modern era of medicine has been the decline in morbidity and mortality associated with bacterial and fungal infections. However, misuse of conventional antibiotics and natural selection of the infectious bacterial population has resulted in the development of varying degrees of drug resistance by most bacterial infectious agents to most antibiotic agents. In severe cases, such as MRSA (Multidrug-Resistant Staph A), one or only a few antibiotics are currently effective. In addition, the existence of immunodeficiency syndromes results in additional incidence of opportunistic infections requiring intensive antibiotic treatment.

Thus, there continues to be a need in the medical arts for novel, more effective, antibiotic compounds, especially for treating bacterial infections, that are resistant to currently available therapies.

Boron containing compounds have received increasing attention as therapeutic agents over the past few years as technology in organic synthesis has expanded to include this atom. [Boron Therapeutics on the horizon, Groziak, M. P.; American Journal of Therapeutics (2001) 8, 321-328] The most notable boron containing therapeutic is the boronic acid bortezomib which was recently launched for the treatment of multiple myeloma. This breakthrough demonstrates the feasibility of using boron containing compounds as pharmaceutical agents. Boron containing compounds have been shown to have various biological activities including herbicides [Organic boron compounds as herbicides. Barnsley, G. E.; Eaton, J. K.; Airs, R. S.; (1957), DE 1016978 19571003], boron neutron capture therapy [Molecular Design and Synthesis of B-10 Carriers for Neutron Capture Therapy. Yamamoto, Y.; Pure Appl. Chem., (1991) 63, 423-426], serine protease inhibition [Borinic acid inhibitors as probes of the factors involved in binding at the active sites of subtilisin Carlsberg and α-chymotrypsin. Simpelkamp, J.; Jones, J. B.; Bioorganic & Medicinal Chemistry Letters, (1992), 2(11), 1391-4], [Design, Synthesis and Biological Evaluation of Selective Boron-containing Thrombin Inhibitors. Weinand, A.; Ehrhardt, C.; Metternich, R.; Tapparelli, C.; Bioorganic and Medicinal Chemistry, (1999), 7, 1295-1307], acetylcholinesterase inhibition [New, specific and reversible bifunctional alkylborinic acid inhibitor of acetylcholinesterase. Koehler, K. A.; Hess, G. P.; Biochemistry (1974), 13, 5345-50] and as antibacterial agents [Boron-Containing Antibacterial Agents: Effects on Growth and Morphology of Bacteria Under Various Culture Conditions. Bailey, P. J.; Cousins, G.; Snow, G. A.; and White, A. J.; Antimicrobial Agents and Chemotherapy, (1980), 17, 549-553]. The boron containing compounds with antibacterial activity can be sub-divided into two main classes, the diazaborinines, which have been known since the 1960's, and dithienylborinic acid complexes. This latter class has been expanded to include many different diarylborinic acid complexes with potent antibacterial activity [Preparation of diarylborinic acid esters as DNA methyl transferase inhibitors. Benkovic, S. J.; Shapiro, L.; Baker, S. J.; Wahnon, D. C.; Wall, M.; Shier, V. K.; Scott, C. P.; Baboval, J.; PCT Int. Appl. (2002), WO 2002044184]. Synthetic developments described in Benkovic et al. enabled creation of a much more diverse class of unsymmetrical di-substituted borinic acid complexes not possible before.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the present invention relates to borinate derivatives as antibiotic compounds especially borinic acid complexes, and include such compounds as derivatives of hydroxyquinolines, picolinic acids and imidazoles.

The antibiotic compounds are also provided as pharmaceutical compositions that can be administered to an animal, most preferably a human, for treatment of a disease having a bacterial or fungal etiology, or an opportunistic infection with a bacteria or fungus in an animal, most preferably a human, in an immunologically compromised or debilitated state of health.

In preferred embodiments, the compounds of the invention are those having the structures given by Formulas 1 or 2, with preferred substituents as disclosed herein.

The invention also provides methods for preparing the antibiotic compounds and pharmaceutical compositions thereof, and methods of using said antibiotics therapeutically. Kits and packaged embodiments of the antibiotic compounds and pharmaceutical compositions of the invention are also contemplated.

The invention also relates to methods of treating infections, preferably bacterial and/or fungal infections, using the antibiotic compounds disclosed herein.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the results of HPLC (high performance liquid chromatography) for several picolinic acid derivatives of the invention.

FIG. 2 shows the results of HPLC (high performance liquid chromatography) for several picolinic acid derivatives of the invention.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides antibiotics, and specifically antibacterial and anti-fungal compounds, useful in treating and/or preventing bacterial infections.

The invention comprises a compound having the structure with formula

wherein B is boron, O is oxygen

wherein R* and R** are each independently selected from substituted or unsubstituted alkyl (C₁-C₄), substituted or unsubstituted cycloalkyl (C₃-C₇), substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted phenyl, and substituted or unsubstituted heteroaryl,

and wherein z is 0 or 1 and when z is 1, A is CH, CR¹⁰ or N,

and wherein D is N, CH, or CR¹²,

and wherein E is H, OH, alkoxy or 2-(morpholino)ethoxy, CO₂H or CO₂alkyl

and wherein m=0-2,

and wherein r is 1 or 2, and wherein when r is 1, G is =0 (double-bonded oxygen) and when r is 2, each G is independently H, methyl, ethyl or propyl,

wherein R¹² is selected from (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, OH, alkoxy, aryloxy, SH, S-alkyl, S-aryl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₂alkyl, SO₃H, SCF₃, CN, halogen, CF₃, NO₂, NH₂, 2*-amino, 3*-amino, NH₂SO₂ and CONH₂,

and wherein J is CR¹⁰ or N

and wherein R⁹, R¹⁰ and R¹¹ are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, (CH₂)_(n)OH (n=2 to 3), CH₂NH₂, CH₂NHalkyl, CH₂N(alkyl)₂, halogen, CHO, CH═NOH, CO₂H, CO₂-alkyl, S-alkyl, SO₂-alkyl, S-aryl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, NH₂, alkoxy, CF₃, SCF₃, NO₂, SO₃H and OH, including salts thereof.

In preferred embodiments of formula 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted alkyl (C₁-C₄) or R* and R** are each a substituted or unsubstituted alkyl (C₁-C₄).

In a preferred embodiment of formulas 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted cycloalkyl (C₃-C₇) or R* and R** are each a substituted or unsubstituted cycloalkyl (C₃-C₇).

In a preferred embodiment of formulas 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted alkenyl or R* and R** are each a substituted or unsubstituted alkenyl. In a further preferred embodiment thereof, the alkenyl has the structure

wherein R¹, R², and R³ are each independently selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, substituted aryl, aralkyl, substituted aralkyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, S-alkyl, S-aryl, SO₂alkyl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₃H, SCF₃, CN, halogen, CF₃ and NO₂.

In a preferred embodiment of formulas 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted alkynyl or R* and R** are each a substituted or unsubstituted alkynyl. In a further preferred embodiment thereof, the alkynyl has the structure

wherein R¹ is selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, S-alkyl, S-aryl, SO₂alkyl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₃H, SCF₃, CN, halogen, CF₃ and NO₂.

In a preferred embodiment of formulas 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted phenyl or R* and R** are each a substituted or unsubstituted phenyl but excluding compounds of formula 1 wherein z is 1, A is CR¹⁰, D is CR¹², J is CR¹⁰ and excluding compounds of formula 2 wherein the combination of substituents is such that z is 1, A is CR¹⁰, D is CR¹², m is 2, and G is H or methyl or ethyl. In a separate embodiment of the foregoing, G is also not propyl. However, in specific embodiments such excluded compounds, although not being claimed as novel, may find use in one or more of the methods of the invention, preferably for treatment against infection, most preferably in treatment against fungal infection. In a preferred embodiment, only novel compounds of the invention are contemplated for such uses.

The novel compounds of the invention do not include quinaldine derivatives, such as 2-methylquinoline, wherein R⁹ is a methyl, A_(z) is CH, D is CH, J is CH and R¹¹ is hydrogen. However, such compounds may be useful in the methods of the invention.

A preferred embodiment is a compound of Formula 2 wherein R* and R** are each other than a phenyl or substituted phenyl.

Another preferred embodiment is a compound of Formula 2 wherein one of R* or R** is benzyl or substituted benzyl.

An additional preferred embodiment is a compound of Formula 2 wherein r is 1, G is ═O, m is 0 and E is OH.

A preferred embodiment is also a compound of Formula 2 wherein z is 1 and R⁹ is selected from alkyl (greater than C₄), (CH₂)_(n)OH (n=1, 2 or 3), CH₂NH₂, CH₂NHalkyl, CH₂N(alkyl)₂, CHO, CH═NOH, CO₂H, CO₂-alkyl, S-alkyl, SO₂-alkyl, S-aryl, alkoxy (greater than C₄), SCF₃, and NO₂.

In one preferred embodiment the compound has the structure of Formula 2 wherein z is 1 and R¹⁰ is selected from alkyl (greater than C₄), (CH₂)_(n)OH (n=1, 2 or 3), CH₂NH₂, CH₂NHalkyl, CH₂N(alkyl)₂, CHO, CH═NOH, CO₂H, CO₂-alkyl, S-alkyl, SO₂-alkyl, S-aryl, alkoxy (greater than C₄), SCF₃, and NO₂.

In another preferred embodiment the compound has the structure of Formula 2 wherein z is 1 and D is CR¹² wherein R¹² is selected from (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, OH, alkoxy (greater than C₄), aryloxy, SH, S-alkyl, S-aryl, SO₂alkyl, SO₃H, SCF₃, CN, NO₂, NH₂SO₂ and CONH₂.

In an additional preferred embodiment the compound has the structure of Formula 2 wherein z is 1, E is N-(morpholinyl)ethoxy or alkoxy greater than C₄. Other preferred embodiments are compounds having the structure of Formula 2 wherein A or D is nitrogen, or wherein m is 2.

In another preferred embodiment, the compound has the structure of Formula 2 wherein one of R* or R** is substituted phenyl substituted with 1 to 5 substituents each of which is independently selected from alkyl (greater than C₆), aryl, substituted aryl, benzyl, substituted benzyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, CONHalkyl, CON(alkyl)₂, OH, alkoxy (greater than C₆), aryloxy, SH, S-alkyl, S-aryl, SO₂alkyl, SO₃H, SCF₃, CN, NO₂, NH₂, 2°-amino, 3°-amino, NH₂SO₂, OCH₂CH₂NH₂, OCH₂CH₂NHalkyl, OCH₂CH₂N(alkyl)₂, oxazolidin-2-yl, and alkyl substituted oxazolidin-2-yl.

In a further preferred embodiment thereof, the phenyl has the structure

wherein R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl aryl, substituted aryl, aralkyl, substituted aralkyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, CONHalkyl, CON(alkyl)₂, OH, alkoxy, aryloxy, SH, S-alkyl, S-aryl, SO₂alkyl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₃H, SCF₃, CN, halogen, CF₃, NO₂, NH₂, 2°-amino, 3°-amino, NH₂SO₂, OCH₂CH₂NH₂, OCH₂CH₂NHalkyl, OCH₂CH₂N(alkyl)₂, oxazolidin-2-yl, or alkyl substituted oxazolidin-2-yl.

One highly preferred embodiment is a compound of formula 1 wherein R* is 3-fluorophenyl, R** is 4-chlorophenyl, R⁹ is H, R¹¹ is H. A_(z) is CH, D is CH, J is CH and may be called (3-fluorophenyl)(4-chlorophenyl)borinic acid 8-hydroxyquinoline ester.

Another preferred embodiment is a compound of formula 1 wherein R* and R** are each 3-(4,4-dimethyloxazolidin-2-yl)phenyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, J is CH and may be called bis(3-(4,4-dimethyloxazolidin-2-yl)phenyl)borinic acid 8-hydroxyquinoline ester.

An additional preferred embodiment is a compound of formula 1 wherein R* is 3-fluorophenyl, R** is cyclopropyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, J is CH and referred to as (3-fluorophenyl)(cyclopropyl)borinic acid 8-hydroxyquinoline ester.

A highly preferred embodiment is a compound of formula 1 wherein R* is 4-(N,N-dimethyl)-aminomethylphenyl, R** is 4-cyanophenyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, J is CH and is referred to as (4-(N,N-dimethyl)-aminomethylphenyl)(4-cyanophenyl)borinic acid 8-hydroxyquinoline ester.

Another highly preferred embodiment is a compound of formula 2 wherein R* is the same as R** which is 3-chloro-4-methylphenyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH and E is OH, m=0, r is 1, G is =0 (double bonded oxygen) and is referred to as bis(3-chloro-4-methylphenyl)borinic acid 3-hydroxypicolinate ester.

A further highly preferred embodiment is a compound of formula 2 wherein R* is the same as R** which is 2-methyl-4-chlorophenyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH and E is OH, m=0, r is 1, G is =0 (double bonded oxygen) and is referred to as bis(2-methyl-4-chlorophenyl)borinic acid 3-hydroxypicolinate ester.

In a preferred embodiment of formula 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted benzyl or R* and R** are each a substituted or unsubstituted benzyl. In a further preferred embodiment thereof, the benzyl has the structure

wherein R⁴, R⁵, R⁶, R⁷ and R⁸ are each independently selected from the group consisting of alkyl, cycloalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, CONHalkyl, CON(alkyl)₂, OH, alkoxy, aryloxy, SH, S-alkyl, S-aryl, SO₂alkyl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₃H, SCF₃, CN, halogen, CF₃, NO₂, NH₂, 2′-amino, 3′-amino, NH₂SO₂, OCH₂CH₂NH₂, OCH₂CH₂NHalkyl, OCH₂CH₂N(alkyl)₂, oxazolidin-2-yl, or alkyl substituted oxazolidin-2-yl.

One preferred embodiment is a compound of formula 1 or 2, R* and/or R** are the same or are different, preferably wherein one of R* and R** is a substituted or unsubstituted heterocycle or R* and R** are each a substituted or unsubstituted heterocycle. In a further preferred embodiment thereof, the heterocycle has the structure

wherein X═CH═CH, N═CH, NR¹³ (wherein R¹³═H, alkyl, aryl or aralkyl), O, or S

and wherein Y═CH or N

and wherein R¹, R², and R³ are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, (CH₂)_(k)OH (where k=1, 2 or 3), CH₂NH₂, CH₂NH-alkyl, CH₂N(alkyl)₂, CO₂H, CO₂alkyl, CONH₂, S-alkyl, S-aryl, SO₂alkyl, SO₂N(alkyl)₂, SO₂NHalkyl, SO₂NH₂, SO₃H, SCF₃, CN, halogen, CF₃, NO₂, oxazolidin-2-yl, or alkyl substituted oxazolidin-2-yl.

A highly preferred embodiment is a compound of formula 1 wherein R* is pyrid-3-yl, R** is 4-chlorophenyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, and J is CH (named (pyrid-3-yl)(4-chlorophenyl)borinic acid 8-hydroxyquinoline ester).

A highly preferred embodiment is a compound of formula 1 wherein R* is 5-cyanopyrid-3-yl, R** is vinyl, R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, and J is CH (named (5-cyanopyrid-3-yl)(vinyl)borinic acid 8-hydroxyquinoline ester).

One preferred embodiment is a compound of formula 1 wherein R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH, and J is CH.

Another preferred embodiment is a compound of formula 2 wherein R⁹ is H, R¹¹ is H, A_(z) is CH, D is CH and E is OH, m=0, r is 1, and G is =0 (double bonded oxygen).

The structures of the invention also permit solvent interactions that may afford structures (such as Formulas 1B and 2B) that include atoms derived from the solvent encountered by the compounds of the invention during synthetic procedures and therapeutic uses. Thus, such solvent structures can especially insinuate themselves into at least some of the compounds of the invention, especially between the boron and nitrogen atoms, to increase the ring size of such compounds by one or two atoms. For example, where the boron ring of a structure of the invention comprises 5 atoms, including, for example, the boron, a nitrogen, an oxygen and 2 carbons, insinuation of a solvent atom between the boron and nitrogen would afford a 7 membered ring. In one example, use of hydroxyl and amino solvents may afford structures containing an oxygen or nitrogen between the ring boron and nitrogen atoms to increase the size of the ring. Such structures are expressly contemplated by the present invention, preferably where R*** is H or alkyl

As used herein, the following terms have the stated meaning:

By “alkyl”, “lower alkyl”, and “C₁-C₆ alkyl” in the present invention is meant straight or branched chain alkyl groups having 1-6 carbon atoms, such as, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl, and 3-methylpentyl.

By “alkoxy”, “lower alkoxy”, and “C₁-C₆ alkoxy” in the present invention is meant straight or branched chain alkoxy groups having 1-6 carbon atoms, such as, for example, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, 2-pentyl, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3-hexoxy, and 3-methylpentoxy.

By the term “halogen” in the present invention is meant fluorine, bromine, chlorine, and iodine.

By “cycloalkyl, e.g., C₃-C₇ cycloalkyl, in the present invention is meant cycloalkyl groups having 3-7 atoms such as, for example cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. In C₃-C₇ cycloalkyl groups, preferably in C₅-C₇ cycloalkyl groups, one or two of the carbon atoms forming the ring can be replaced with a hetero atom, such as sulfur, oxygen or nitrogen. Examples of such groups are piperidinyl, piperazinyl, morpholinyl, pyrrolidinyl, imidazolidinyl, oxazolidinyl, perhydroazepinyl, perhydrooxazapinyl, oxepanyl, and perhydro-oxepanyl. C₃ and C₄ cycloalkyl groups having a member replaced by nitrogen or oxygen include aziridinyl, azetidinyl, oxetanyl, and oxiranyl.

By “aryl” is meant an aromatic carbocyclic group having a single ring (e.g., phenyl), multiple rings (e.g., biphenyl), or multiple condensed rings in which at least one is aromatic, (e.g., 1,2,3,4-tetrahydronaphthyl, naphthyl, anthryl, or phenanthryl), which is optionally mono-, di-, or trisubstituted with, e.g., halogen, lower alkyl, lower alkoxy, lower alkylthio, trifluoromethyl, lower acyloxy, aryl, heteroaryl, and hydroxy. Preferred aryl groups include phenyl and naphthyl, each of which is optionally substituted as defined herein.

By “heteroaryl” is meant one or more aromatic ring systems of 5-, 6-, or 7-membered rings containing at least one and up to four heteroatoms selected from nitrogen, oxygen, or sulfur. Such heteroaryl groups include, for example, thienyl, furanyl, thiazolyl, imidazolyl, (is)oxazolyl, pyridyl, pyrimidinyl, (iso)quinolinyl, napthyridinyl, benzimidazolyl, and benzoxazolyl. Preferred heteroaryls are thiazolyl, pyrimidinyl, preferably pyrimidin-2-yl, and pyridyl. Other preferred heteroaryl groups include 1-imidazolyl, 2-thienyl, 1-(or 2-)quinolinyl, 1-(or 2-) isoquinolinyl, 1-(or 2-)tetrahydroisoquinolinyl, 2-(or 3-)furanyl and 2-tetrahydro-furanyl.

By “ligand” is meant a nitrogen-containing aromatic system which is capable of forming a dative bond with the Lewis acidic boron center, while appended as a borinate ester moiety. Such ligands are known to those trained in the arts. Examples are shown in the

-   -   The compounds of the present invention have been implicated in         the inhibition of key microbial enzymes, such as bacterial DNA         methyltransferase. Many of the compounds disclosed herein are         selective inhibitors of methyltransferases in microbes, while         not inhibitory for methyltransferases in mammals. However, the         anti-bacterial and anti-fungal activity of the compounds of the         invention is not limited to those with         said enzyme inhibitory activity, nor is the latter effect         necessarily essential to said therapeutic activity.

The invention also provides embodiments of the compounds disclosed herein as pharmaceutical compositions. The pharmaceutical compositions of the present invention can be manufactured in a manner that is itself known, e.g., by means of a conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes.

Pharmaceutical compositions for use in accordance with the present invention thus can be formulated in conventional manner using one or more physiologically acceptable carriers comprising excipients and auxiliaries that facilitate processing of the active compounds into preparations that can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen.

Non-toxic pharmaceutical salts include salts of acids such as hydrochloric, phosphoric, hydrobromic, sulfuric, sulfinic, formic, toluenesulfonic, methanesulfonic, hydroxyethanesulfonic, nitric, benzoic, citric, tartaric, maleic, fumaric hydroiodic, alkanoic such as acetic, HOOC—(CH₂)_(n)—CH₃ where n is 0-4, and the like. Non-toxic pharmaceutical base addition salts include salts of bases such as sodium, potassium, calcium, ammonium, and functional equivalents. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts.

For injection, the compounds of the invention can be formulated in appropriate aqueous solutions, such as physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. For transmucosal and transcutaneous administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

For oral administration, the compounds can be formulated readily by combining the active compounds with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as tablets, pills, capsules, liquids, gels, syrups, slurries, suspensions and the like, for oral ingestion by a patient to be treated. Pharmaceutical preparations for oral use can be obtained with solid excipient, optionally grinding a resulting mixture, and processing the mixture of granules, after adding suitable auxiliaries, if desired, to obtain tablets. Suitable excipients are, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol; cellulose preparations such as, for example, maize starch, wheat starch, rice starch, potato starch, gelatin, gum hydrophobic polymers containing the therapeutic agent. Various sustained-release materials have been established and are well known by those skilled in the art. Sustained-release capsules can, depending on their chemical nature, release the compounds for a few weeks up to over 100 days. Depending on the chemical nature and the biological stability of the therapeutic reagent, additional strategies for protein and nucleic acid stabilization can be employed.

The pharmaceutical compositions also can comprise suitable solid or gel phase carriers or excipients. Examples of such carriers or excipients include but are not limited to calcium carbonate, calcium phosphate, various sugars, starches, cellulose derivatives, gelatin, and polymers such as polyethylene glycols.

The compounds of the invention can be provided as salts with pharmaceutically compatible counterions. Pharmaceutically compatible salts can be formed with many acids, including but not limited to hydrochloric, sulfuric, acetic, lactic, tartaric, malic, succinic, phosphoric, hydrobromic, sulfinic, formic, toluenesulfonic, methanesulfonic, nitic, benzoic, citric, tartaric, maleic, hydroiodic, alkanoic such as acetic, HOOC—(CH₂)_(n)—CH₃ where n is 0-4, and the like. Salts tend to be more soluble in aqueous or other protonic solvents that are the corresponding free base forms. Non-toxic pharmaceutical base addition salts include salts of bases such as sodium, potassium, calcium, ammonium, and the like. Those skilled in the art will recognize a wide variety of non-toxic pharmaceutically acceptable addition salts.

For topical administration, the compounds can be formulated readily by combining the active compounds with pharmaceutically acceptable carriers well known in the art. Such carriers enable the compounds of the invention to be formulated as gels, slurries, suspensions and ointments for topical applications. If desired, disintegrating agents can be added, such as the cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate.

Pharmaceutical compositions of the compounds of the present invention can be formulated and administered through a variety of means, including systemic, localized, or topical administration. Techniques for formulation and administration can be found in “Remington's Pharmaceutical Sciences,” Mack Publishing Co., Easton, Pa. The mode of administration can be selected to maximize delivery to a desired target site in the body. Suitable routes of administration can, for example, include oral, rectal, transmucosal, transcutaneous, or intestinal administration. Parenteral delivery, including intramuscular, subcutaneous, and intramedullary injections, as well as intrathecal, direct intraventricular, intravenous, intraperitoneal, intranasal, or intraocular injections are also contemplated.

Alternatively, one can administer the compound in a local rather than systemic manner, for example, via injection of the compound directly into a specific tissue, often in a depot or sustained release formulation.

Pharmaceutical compositions suitable for use in the present invention include compositions wherein the active ingredients are contained in an effective amount to achieve its intended purpose. More specifically, a therapeutically effective amount means an amount effective to prevent development of or to alleviate the existing symptoms of the subject being treated. Determination of the effective amounts is well within the capability of those skilled in the art, especially in light of the detailed disclosure provided herein.

For any compound used in the method of the invention, the therapeutically effective dose can be estimated initially from cell culture assays, as disclosed herein. For example, a dose can be formulated in animal models to achieve a circulating concentration range that includes the EC₅₀ (effective dose for 50% increase) as determined in cell culture, i.e., the concentration of the test compound which achieves a half-maximal inhibition of bacterial cell growth. Such information can be used to more accurately determine useful doses in humans.

It will be understood, however, that the specific dose level for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination, the severity of the particular disease undergoing therapy and the judgment of the prescribing physician.

For administration to non-human animals, the drug or a pharmaceutical composition containing the drug may also be added to the animal feed or drinking water. It will be convenient to formulate animal feed and drinking water products with a predetermined dose of the drug so that the animal takes in an appropriate quantity of the drug along with its diet. It will also be convenient to add a premix containing the drug to the feed or drinking water approximately immediately prior to consumption by the animal.

Preferred compounds of the invention will have certain pharmacological properties. Such properties include, but are not limited to, oral bioavailability, low toxicity, low serum protein binding and desirable in vitro and in vivo half-lives. Assays may be used to predict these desirable pharmacological properties. Assays used to predict bioavailability include transport across human intestinal cell monolayers, including Caco-2 cell monolayers. Serum protein binding may be predicted from albumin binding assays. Such assays are described in a review by Oravcova et al. (1996, J. Chromat. B 677: 1-27). Compound half-life is inversely proportional to the frequency of dosage of a compound. In vitro half-lives of compounds may be predicted from assays of microsomal half-life as described by Kuhnz and Gieschen (Drug Metabolism and Disposition, (1998) volume 26, pages 1120-1127).

Toxicity and therapeutic efficacy of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD₅₀ (the dose lethal to 50% of the population) and the ED₅₀ (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio between LD₅₀ and ED₅₀. Compounds that exhibit high therapeutic indices are preferred. The data obtained from these cell culture assays and animal studies can be used in formulating a range of dosage for use in humans. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED₅₀ with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration utilized. The exact formulation, route of administration and dosage can be chosen by the individual physician in view of the patient's condition. (See, e.g. Fingl et al., 1975, in “The Pharmacological Basis of Therapeutics”, Ch.1, p. 1).

Dosage amount and interval can be adjusted individually to provide plasma levels of the active moiety that are sufficient to maintain bacterial cell growth inhibitory effects. Usual patient dosages for systemic administration range from 100-2000 mg/day. Stated in terms of patient body surface areas, usual dosages range from 50-910 mg/m²/day. Usual average plasma levels should be maintained within 0.1-1000 μM. In cases of local administration or selective uptake, the effective local concentration of the compound cannot be related to plasma concentration.

The compounds of the invention are useful as antibiotics for the treatment of diseases of both animals and humans, including but not limited to actinomycosis, anthrax, bacterial dysentery, botulism, brucellosis, cellulitis, cholera, conjunctivitis, cystitis, diphtheria, bacterial endocarditis, epiglottitis, gastroenteritis, glanders, gonorrhea, Legionnaire's disease, leptospirosis, bacterial meningitis, plague, bacterial pneumonia, puerperal sepsis, rheumatic fever, Rocky Mountain spotted fever, scarlet fever, streptococcal pharyngitis, syphilis, tetanus, tuberculosis, tularemia, typhoid fever, typhus, and pertussis.

The disclosures in this application of all articles and references, including patents and patent applications, are incorporated herein by reference in their entirety.

The compounds of the invention comprise a novel class of broad-spectrum antibiotics. Medically-important bacterial species that provide appropriate targets for the antibacterial activity of the inhibitors of the invention include gram-positive bacteria, including cocci such as Staphylococcus species and Streptococcus species; acid-fast bacterium, including Mycobacterium species; bacilli, including Bacillus species, Corynebacterium species and Clostridium species; filamentous bacteria, including Actinomyces species and Streptomyces species; gram-negative bacteria, including cocci such as Neisseria species and Acinetobacter species; bacilli, such as Pseudomonas species, Brucella species, Agrobacterium species, Bordetella species, Escherichia species, Shigella species, Yersinia species, Salmonella species, Klebsiella species, Enterobacter species, Haemophilus species, Pasteurella species, and Streptobacillus species; spirochetal species, Campylobacter species, Vibrio species; and intracellular bacteria including Rickettsiae species and Chlamydia species.

Specific bacterial species that are targets for the antibiotics of the invention include Staphylococcus aureus; Staphylococcus epidermidis, Staphylococcus saprophyticus; Streptococcus pyogenes; Streptococcus agalactiae; Streptococcus pneumoniae; Enterococcus faecalis; Enterococcus faecium; Bacillus anthracis; Mycobacterium avium, Mycobacterium tuberculosis, Acinetobacter baumannii; Corynebacterium diphtheria; Clostridium perfringens; Clostridium botulinum; Clostridium tetani; Neisseria gonorrhoeae; Neisseria meningitidis; Pseudomonas aeruginosa; Legionella pneumophila; Escherichia coli; Yersinia pestis; Haemophilus influenzae; Helicobacter pylori; Campylobacter fetus; Campylobacter jejuni; Vibrio cholerae; Vibrio parahemolyticus; Trepomena pallidum; Actinomyces israelii; Rickettsia prowazekii; Rickettsia rickettsii; Chlamydia trachomatis; Chlamydia psittaci; Brucella abortus; Agrobacterium tumefaciens; and Francisella tularensis.

Medically-important fungal and yeast species that provide appropriate targets for the antifungal activity of the inhibitors of the invention include Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, Trichophyton mentagrophytes, Microporium canis, Aspergillus species, Cryptococcus neoformans, Blastomyces dermatitidis, Coccidiodes immitis, Histoplasma capsulatum and Paracoccidioides brasiliensis.

In carrying out the procedures of the present invention it is of course to be understood that reference to particular buffers, media, reagents, cells, culture conditions and the like are not intended to be limiting, but are to be read so as to include all related materials that one of ordinary skill in the art would recognize as being of interest or value in the particular context in which that discussion is presented. For example, it is often possible to substitute one buffer system or culture medium for another and still achieve similar, if not identical, results. Those skilled in the art will have sufficient knowledge of such systems and methodologies so as to be able, without undue experimentation, to make such substitutions as will optimally serve their purposes in using the methods and procedures disclosed herein.

The invention is described in more detail in the following non-limiting examples. It is to be understood that these methods and examples in no way limit the invention to the embodiments described herein and that other embodiments and uses will no doubt suggest themselves to those skilled in the art.

The compounds of this invention are evaluated for their antibacterial activity as per the guidelines and procedures prescribed by the National Committee for Clinical Laboratory Standards (NCCLS) (cf., NCCLS Document M7-A3, 1993-Antimicrobial Susceptibility Testing).

Protocol for MIC Determination

A useful protocol for MIC determination is as follows:

1. Approximately 2.5 mg of the compounds to be tested was weighed into cryovials.

2. 5 mg/ml stock solutions were made by adding DMSO to the samples accordingly.

3. 256 μg/ml working solutions were made by using the 5 mg/ml stock solutions and adding sterile distilled water accordingly.

4. A Beckman 2000 Automated Workstation was programmed to load 96 well plates with broth and compounds as follows:

-   -   100 μl of the appropriate broth was added to columns 1-11     -   200 μl of the appropriate broth was added to column 12     -   100 μl of compounds at the 256 μg/ml working solution were added         to column 1 (one compound per row)     -   Two-fold serial dilutions were done from column 1 to 10     -   Column 11 served as the growth control

5. The 10 organism panel was plated from stock vials stored at −80° C. and incubated for 24 hours at 34° C. The organisms were then sub-cultured and incubated for 24 hours at 34° C.

-   -   The inoculums were first prepared in sterile distilled water         with a target of 0.09-0.11 absorbance at 620 nm wavelength     -   A 1/100 dilution was made into the appropriate broth     -   100 μl of broth with organism was added to columns 1-11     -   Column 12 served as the blank control

6. The completed 96 well plates were incubated for 24 hours at 34° C. The 96 well plates were then read using a Beckman Automated Plate Reader at 650 nm wavelength. The MIC was determined through calculations involving the growth control (column 11) and blank control (column 12).

Protocol for Antifungal in vitro MIC Determination

A useful protocol for antifungal activity determination is described below.

Preparation

Media is prepared 1-2 weeks before the start of the experiment. Media is stored in the cold room (4° C.) prior to use.

Sabouraud Dextrose Agar Plates:

-   -   1. Add 65 g of powdered of Sabouraud Dextrose Agar media into IL         of dH₂O with gentle stirring     -   2. Autoclave at 121° C. and 22 psi for 15 minutes     -   3. Allow the media to cool to ˜50° C.     -   4. Pour media into 100×15 mm sterile petri dishes with 20 ml         aliquots

RPMI 1640+MOPS Broth:

-   -   1 Add 1 packet of powdered RPMI media to IL of dH₂O (15° C.-30°         C.) with gentle stirring     -   2. Add 2 g of NaHCO₃     -   3. Add 34.5 g of MOPS     -   4. Adjust the pH to 7.0 using NaOH or HCl     -   5. Sterilize with membrane filtration (0.22 micron cellulose         acetate filter)

Sterile Saline (0.9%)

-   -   1. Dissolve 9 g of NaCl to IL of dH₂O     -   2. Autoclave at 121° C. and 22 psi for 15 minutes

Sterile dH₂O

-   -   1. Autoclave dH₂O at 121° C. and 22 psi for 15 minutes         Procedure

1. The 10 organism panel is plated from stock vials stored at −80° C. (suspended in broth with 20% glycerol) and incubated at 37° C. for 24 hours. The organisms are then sub-cultured and incubated at 37° C. for 24 hours. These will be used to prepare fresh inoculums for Step 6.

2. Approximately 2.5 mg of the compounds to be tested are weighed into 2 ml cryovials. Fluconazole, Amphotericin B and Itraconazole are tested as reference compounds.

3. 5 mg/ml stock solutions are made by adding DMSO to the samples accordingly. Compounds insoluble with vortexing only are sonicated.

4. 256 μg/ml working solutions are made by using the 5 mg/ml stock solutions and adding sterile distilled water accordingly.

5. 96-well plates are used for MIC determination. Each of the 8 rows can be used to test a different compound. Compounds are loaded into the first column and two-fold dilutions of are made from column 1 to 10. Column 11 is a growth control (no compound) and column 12 is a blank control (no compound or organism). Manual addition of broth and compounds is performed as follows:

-   -   100 μl of RPMI+MOPS broth is added to columns 1-11     -   200 μl of RPMI+MOPS broth is added to column 12     -   100 μl of compounds at the 256 μg/ml working solution are added         to column 1 (one compound per row)     -   Two-fold serial dilutions are done from column 1 to 10     -   Column 11 serves as the growth control (media+organism only)

6. The sub-cultured organisms are used to prepare fresh inoculums for testing on the 96-well plates. Each 96-well plate will test a different organism.

-   -   Colonies from the sub-cultured organisms (Step 1) are used to         prepare inoculums with sterile saline. The target is adjusted to         70-75% transmittance at 530 nm wavelength using a Novospec II         spectrophotometer.     -   A 1/1000 dilution is made into RPMI+MOPS broth     -   100 □l of this broth with organism is added to columns 1-11         (column 12 serves as the blank control)

7. The completed 96-well plates are incubated at 37° C. for 24 hours. The 96 well plates are then read for absorbance at 650 nm wavelength using a Biomek Automated Plate Reader.

Calculations

The absorbance readings from the Biomek Automated Plate Reader are used to determine the percent inhibition for each test well. The formula used is as follows: % Inhibition=[1−(ABS_(test)−ABS_(blank))/(ABS_(mean growth)−ABS_(blank))]×100%

-   -   ABS_(test): Absorbance of the test well     -   ABS_(blank): Absorbance of the blank well in the same row as the         test well (column 12)     -   ABS_(mean growth): Mean absorbance of the growth control wells         (column 11)

The minimum inhibitory concentration (MIC) is found at the lowest concentration of compound where percent inhibition is greater than or equal to 80%.

These procedures were used to obtain the results in the following tables. Representative microbiological data for the compounds 10 to 123 are shown in Tables 1 to 4 as MIC (Minimum Inhibitory Concentration) with the values expressed as micrograms per ml.

Thus, the invention provides antibiotics that are generically called borinic acid complexes, most preferably derived from disubstituted borinic acids.

Borinate Complexes

The synthesis of the compounds of the invention is accomplished in several formats. Reaction scheme #1 demonstrates the synthesis of the intermediate borinic acids, and their subsequent conversion to the desired borinic acid complexes. When R* and R** are identical, the reaction of two equivalents of an arylmagnesium halide (or aryllithium) with trialkyl borate, followed by acidic hydrolysis affords the desired borinic acid 5. When R* and R** are not identical, the reaction of one equivalent of an arylmagnesium halide (or aryllithium) with appropriate aryl(dialkoxy)borane (4), heteroaryl(dialkoxy)borane or alkyl(dialkoxy)borane (alkoxy group comprised of methoxy, ethoxy, isopropoxy, or propoxy moiety), followed by acidic hydrolysis affords the unsymmetrical borinic acids 6 in excellent yields. Where applicable, the reaction of the alkylene esters (3, T=nothing, CH₂, CMe₂) with the appropriate organocerium, organolithium, organomagnesium or equivalent reactant is convenient.

As shown in Scheme 1, the borinic acid complexes are obtained from the precursor borinic acids by reaction with one equivalent of the desired heterocyclic ligand in suitable solvents (i.e., ethanol, isopropanol, dioxane, ether, toluene, dimethylformamide, N-methylpyrrolidone, or tetrahydrofuran).

In certain situations, compounds of the invention may contain one or more asymmetric carbon atoms, so that the compounds can exist in different stereoisomeric forms. These compounds can be, for example, racemates or optically active forms. In these situations, the single enantiomers, i.e., optically active forms, can be obtained by asymmetric synthesis or by resolution of the racemates. Resolution of the racemates can be accomplished, for example, by conventional methods such as crystallization in the presence of a resolving agent, or chromatography, using, for example a chiral HPLC column.

Unexpected Stability of Picolinic Acid Complexes

During the preparation of compounds of Formula 2 we found that complexes containing hydroxymethyl-type borinic esters, e.g., 2-hydroxymethyl-pyridine (R⁹ is H, A is CH, D is CH, E is H, m is 0, r is 2, G is H) were not stable under typical HPLC conditions. For example, the 2-hydroxymethylpyridine complexes shown in FIGS. 1A and 1B both eluted as two peaks, one with the solvent front and one much later, indicating some manner of degradation had occurred during the HPLC process. This posed a serious problem. Instability issues prevent this class of compound from being developed as drug candidates. However, it was subsequently found that picolinic acid complexes (e.g., R⁹ is H, A is CH, D is CH, E is H, m is 0, r is 1, G is =0 (double bonded oxygen)) were stable under identical the same HPLC conditions. For example, the picolinic acid complexes shown in FIGS. 2A and 2B show the complex to elute as a single peak indicating no breakdown of the complex. The biological activities of the picolinic acid class are comparable to or better than the hydroxymethylpyridine complexes making the picolinic acid complexes an ideal drug development candidate. HPLC conditions Sample preparation: ˜1 mg/mL dissolved in 100% acetonitrile Column: BetaBasic C18 5um 150 × 4.6 mm Flow rate: 1 mL/min Injection vol: 10 uL Wavelength: PDA 200-450 nm; 254 nm reported Mobile phase: Solvent A: 0.1% H₃PO₄ in water Solvent B: Acetonitrile Gradient Method: Time (min) % A % B  0 95 5  1 95 5 11 0 100 21 0 100

Representative compounds of the present invention include, but are not limited to, the compounds disclosed herein and their pharmaceutically acceptable acid and base addition salts. In addition, if the compound of the invention is obtained as an acid addition salt, the free base can be obtained by basifying a solution of the acid salt. Conversely, if the product is a free base, an addition salt, particularly a pharmaceutically acceptable addition salt, may be produced by dissolving the free base in a suitable organic solvent and treating the solution with an acid, in accordance with conventional procedures for preparing acid addition salts from base compounds. In a preferred embodiment, the compounds of the invention comprise any of compounds 10-123 (Tables 1, 2, 3 and 4), and variants thereof. TABLE 1 Antibacterial Profile Against Select Gram-positive and Gram-negative Pathogens S. S. S. E. M. aureus epidermidis pneumoniae faecalis E. catarrhalis ATCC ATCC ATCC ATCC faecium ATCC Cmp R* R** Ligand 29213 12228 6301 29212 CT-26 25238 10 3-ClC₆H₄ 3-ClC₆H₄ 8-hydroxyquinoline 1 2 2 32 4 NA 11 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 4-hydroxybenzimidazole 0.125 4 NA 8 8 NA 12 3-ClC₆H₄ 3-ClC₆H₄ 5-fluoro-8-hydroxyquinoline 0.125 2 2 8 4 2 13 3-ClC₆H₄ 3-ClC₆H₄ 5-chloro-8-hydroxyquinoline 0.125 1 1 64 2 0.25 14 3-ClC₆H₄ 3-ClC₆H₄ 4-methyl-8-hydroxyquinoline 0.125 1 1 64 4 0.5 15 2-F-4-ClC₆H₃ 3-FC₆H₄ 8-hydroxyquinoline 0.125 1 2 16 4 0.5 16 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 2-HO₂C-4-hydroxy-5,7- 0.25 0.5 NA 0.5 0.25 NA dichloroquinoline 17 3-ClC₆H₄ 3-ClC₆H₄ 2-amino-8-hydroxyquinoline 0.25 2 2 8 8 2 18 3-ClC₆H₄ 3-Cl-4-FC₆H₃ 8-hydroxyquinoline 0.25 1 2 8 4 1 19 3-ClC₆H₄ 3-ClC₆H₄ 5-cyano-8-hydroxyquinoline 0.25 2 4 16 4 0.5 20 3-ClC₆H₄ 3-Cl-5-FC₆H₃ 8-hydroxyquinoline 0.25 1 2 8 4 2 21 3-ClC₆H₄ 3-FC₆H₄ 5-cyano-8-hydroxyquinoline 0.5 4 2 16 8 0.25 22 3-ClC₆H₄ 3-FC₆H₄ 5-nitro-8-hydroxyquinoline 0.5 4 2 64 16 0.12 23 3-ClC₆H₄ 3-FC₆H₄ 5-chloro-7-chloro-8- 0.5 16 8 64 16 0.12 hydroxyquinoline 24 3-ClC₆H₄ 3-FC₆H₄ 5-bromo-7-bromo-8- 0.5 8 8 64 32 0.12 hydroxyquinoline 25 3-ClC₆H₄ 3-FC₆H₄ 2-carboxy-4-hydroxy-8- 0.5 8 2 16 16 2 methoxyquinoline 26 2-thienyl Me 8-hydroxyquinoline 0.5 1 NA 4 4 NA 27 3-NCC₆H₄ 4-Me-3-ClC₆H₃ 8-hydroxyquinoline 0.5 1 1 8 2 1 28 3,4-Cl₂C₆H₃ 3-FC₆H₄ 8-hydroxyquinoline 0.5 1 2 4 2 1 29 2,4-Cl₂C₆H₃ 3-FC₆H₄ 8-hydroxyquinoline 0.5 1 2 8 2 0.5 30 3,4-Cl₂C₆H₃ 3,4-Cl₂C₆H₃ 8-hydroxyquinoline 1 0.5 NA 2 2 NA 31 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 2-carboxy-4-hydroxyquinoline 1 1 NA 2 1 NA 32 3-ClC₆H₄ 3-FC₆H₄ 8-hydroxyquinoline 1 1 1 16 2 2 33 3-Cl-5-FC₆H₃ 3-MeC₆H₄ 8-hydroxyquinoline 1 1 1 8 2 2 34 3-ClC₆H₄ 3-FC₆H₄ 5-fluoro-8-hydroxyquinoline 1 2 2 8 4 1 35 3-ClC₆H₄ 3-MeSC₆H₄ 5-fluoro-8-hydroxyquinoline 1 2 2 8 4 2 36 3-ClC₆H₄ 2-thienyl 8-hydroxyquinoline 1 1 2 8 2 4 37 3-Me-4-ClC₆H₃ 3-NCC₆H₄ 8-hydroxyquinoline 1 1 1 8 2 1 38 2-FC₆H₄ 3-NCC₆H₄ 8-hydroxyquinoline 1 1 2 16 2 1 39 3-ClC₆H₄ 3-NCC₆H₄ 8-hydroxyquinoline 1 1 1 8 2 2 40 3-NCC₆H₄ Vinyl 8-hydroxyquinoline 1 1 1 8 2 2 41 3-NCC₆H₄ Ethynyl 8-hydroxyquinoline 1 1 1 4 2 1 42 3-FC₆H₄ Ethynyl 8-hydroxyquinoline 1 1 1 8 2 1 43 2-ClC₆H₄ Ethynyl 8-hydroxyquinoline 1 1 1 8 2 1 44 Ethynyl Ethynyl 8-hydroxyquinoline 1 1 1 16 2 0.25 45 3,5-F₂C₆H₃ Ethynyl 8-hydroxyquinoline 1 1 1 8 1 1 46 3,5-Cl₂C₆H₃ Ethynyl 8-hydroxyquinoline 1 1 1 4 1 1 47 3,4-Cl₂C₆H₃ Ethynyl 8-hydroxyquinoline 1 1 1 8 2 1 48 3-Cl-4-FC₆H₃ Ethynyl 8-hydroxyquinoline 1 1 1 8 2 2 49 4-ClC₆H₄ 4-ClC₆H₄ 5-chloro-8-hydroxyquinoline 2 1 1 16 2 0.25 50 4-ClC₆H₄ 4-ClC₆H₄ 8-hydroxyquinoline 2 2 2 4 4 NA 51 3-FC₆H₄ 3-FC₆H₄ 8-hydroxyquinoline 2 1 NA 8 2 NA 52 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 8-hydroxyquinoline 2 4 NA 8 16 NA 53 3-NCC₆H₄ 3-NCC₆H₄ 8-hydroxyquinoline 2 2 NA 64 4 2 54 4-ClC₆H₄ 4-Cl-3-FC₆H₃ 8-hydroxyquinoline 2 1 2 8 4 1 55 4-Cl-3-FC₆H₃ 4-Cl-3-FC₆H₃ 8-hydroxyquinoline 2 1 2 4 2 4 56 3-MeC₆H₄ 3,5-Cl₂C₆H₃ 8-hydroxyquinoline 2 2 2 8 4 4 57 4-ClC₆H₄ 4-FC₆H₄ 5-fluoro-8-hydroxyquinoline 2 2 4 16 4 1 58 3-ClC₆H₄ 4-FC₆H₄ 5-fluoro-8-hydroxyquinoline 2 2 2 8 4 0.5 59 3-ClC₆H₄ 4-MeSC₆H₄ 8-hydroxyquinoline 2 1 1 8 4 2 60 4-ClC₆H₄ 3-MeSC₆H₄ 8-hydroxyquinoline 2 1 2 8 4 2 61 3-ClC₆H₄ cyclopropyl 8-hydroxyquinoline 2 1 1 16 2 2 62 4-ClC₆H₄ 3-MeSC₆H₄ 5-fluoro-8-hydroxyquinoline 2 2 2 8 4 2 63 4-ClC₆H₄ 4-MeSC₆H₄ 8-hydroxyquinoline 2 1 2 8 4 1 64 4-ClC₆H₄ 4-MeSC₆H₄ 5-fluoro-8-hydroxyquinoline 2 2 4 8 8 1 65 4-ClC₆H₄ 4-Cl-3-HOC₆H₃ 8-hydroxyquinoline 2 2 2 16 4 4 66 4-ClC₆H₄ 3-FC₆H₄ 4-methyl-8-hydroxyquinoline 2 1 1 64 4 0.5 67 3-ClC₆H₄ 3-(DMISO)C₆H₄ 4-methyl-8-hydroxyquinoline 2 1 1 64 4 0.5 68 3-FC₆H₄ 3-(DMISO)C₆H₄ 8-hydroxyquinoline 2 2 16 32 4 0.12 69 3-(DMISO)C₆H₄ cyclopropyl 8-hydroxyquinoline 2 1 2 64 4 1 70 3-FC₆H₄ cyclopropyl 8-hydroxyquinoline 2 1 1 64 2 0.5 71 3-FC₆H₄ 4-NCC₆H₄ 5-chloro-7-chloro-8- 2 2 8 64 4 0.12 hydroxyquinoline 72 3-(DMISO)C₆H₄ 3-(DMISO)C₆H₄ 8-hydroxyquinoline 4 2 4 64 4 NA 73 3-(DMISO)C₆H₄ Vinyl 8-hydroxyquinoline 2 1 2 64 8 0.25 74 4-FC₆H₄ 4-NCC₆H₄ 8-hydroxyquinoline 2 1 2 32 2 1 75 3-ClC₆H₄ 3-MeSC₆H₄ 8-hydroxyquinoline 2 1 2 64 4 NA 76 4-Me-3-ClC₆H₃ 2-thienyl 8-hydroxyquinoline 2 1 NA 8 4 NA 77 3-ClC₆H₄ 2-MeC₆H₄ 8-hydroxyquinoline 2 1 1 8 4 2 78 3-ClC₆H₄ 2-MeOC₆H₄ 8-hydroxyquinoline 2 1 1 8 2 2 79 3-ClC₆H₄ 2-Me-4-ClC₆H₃ 8-hydroxyquinoline 2 2 2 8 4 2 80 4-Cl-3-MeC₆H₃ 4-Cl-3-MeC₆H₃ 8-hydroxyquinoline 2 1 2 4 4 2 81 3-ClC₆H₄ 3-Cl-6-MeOC₆H₃ 8-hydroxyquinoline 2 1 2 8 4 2 82 3,5-Cl₂C₆H₃ 4-(Me₂NC₂H₄)OC₆H₄ 8-hydroxyquinoline 2 2 2 8 2 4 83 4-BrC₆H₄ 4-(Me₂NC₂H₄)OC₆H4 8-hydroxyquinoline 2 1 2 4 4 2 84 3-ClC₆H₄ 4-F-3-MeC₆H₃ 8-hydroxyquinoline 2 1 2 8 4 4 85 3-Me-4-ClC₆H₃ 3-F-4-ClC₆H₃ 8-hydroxyquinoline 2 1 2 4 4 2 86 3-FC₆H₄ 4-Cl-3-MeC₆H₃ 8-hydroxyquinoline 2 1 2 8 4 2 87 3-FC₆H₄ 3-F-4-ClC₆H₃ 8-hydroxyquinoline 2 1 2 8 4 1 88 3-Cl-6-FC₆H₃ 3-NCC₆H₄ 8-hydroxyquinoline 2 2 2 8 2 2 89 2,5-F₂C₆H₃ 3-NCC₆H₄ 8-hydroxyquinoline 2 1 1 8 2 2 90 4-F-3-ClC₆H₃ 3-NCC₆H₄ 8-hydroxyquinoline 2 2 1 8 2 2 91 3-Me-4-ClC₆H₃ 4-NCC₆H₄ 8-hydroxyquinoline 2 1 2 8 2 1 92 2,5-F₂C₆H₃ 4-NCC₆H₄ 8-hydroxyquinoline 2 1 2 8 4 1 93 3-Cl-6-FC₆H₃ 4-NCC₆H₄ 8-hydroxyquinoline 2 1 1 8 4 1 94 3-Cl-6-MeOC₆H₃ 4-NCC₆H₄ 8-hydroxyquinoline 2 1 1 8 4 2 95 4-NCC₆H₄ Ethynyl 8-hydroxyquinoline 2 1 2 8 2 1 96 4-ClC₆H₄ 3,4-F₂C₆H₃ 8-hydroxyquinoline 2 1 2 8 2 1 97 4-ClC₆H₄ 4-Me-3-FC₆H₃ 8-hydroxyquinoline 2 1 1 8 2 1 98 4-ClC₆H₄ 3,5-F₂C₆H₃ 8-hydroxyquinoline 2 1 1 8 4 1 99 3-CF₃-4-ClC₆H₃ 3-FC₆H₄ 8-hydroxyquinoline 2 1 2 8 2 1 100  4-ClC₆H₄ 3-F-5-CF₃C₆H₃ 8-hydroxyquinoline 2 1 2 4 2 1 Ciprofloxacin 0.125 0.125 0.5 0.5 64 0.125 Cloxacillin 0.125 0.25 0.125 16 64 1 Imipenem 0.125 0.125 0.125 1 64 0.125 Ceftriaxone 2 1 0.125 64 64 0.125 Meropenem 0.06 0.06 2 Erythromycin 0.5 0.5 2 Pen G 0.5 16 0.125 1 32 0.125 DMISO = 4,4-dimethyloxazolin-2-yl

TABLE 2 Antibacterial Profile Against Select Gram-positive and Gram-negative Pathogens S. S. S. E. H. aureus epidermidis pneumonia faecalis E. influenzae ATCC ATCC ATCC ATCC faecium ATCC Cmp R* R** Ligand 29213 12228 6301 29212 CT-26 49766 101 3-ClC₆H₄ 3-ClC₆H₄ 1-(2-marpholino-4-yl-ethyl)- 0.12 4 16 64 64 4 imidazoleacetate 102 3-ClC₆H₄ 3-ClC₆H₄ 2-hydroxyisopropyl-3- 0.5 1 0.25 64 2 64 hydroxypyridine 103 4-ClC₆H₄ 4-ClC₆H₄ 2-hydroxyisopropyl-3- 0.25 0.5 0.5 4 1 64 hydroxypyridine 104 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 2-hydroxymethyl-1N- 0.5 4 NA 16 32 8 benzylimidazole 105 3-ClC₆H₄ 3-ClC₆H₄ 2-hydroxymethylpyridine 0.125 4 4 32 32 4 106 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 2-pyridylacetic acid 0.5 4 NA 64 64 64 107 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-(2-hydroxyethoxy)picolinic 0.125 4 NA 16 8 32 acid 108 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-(N- 0.25 4 NA 4 2 64 morpholinylethoxy)picolinic acid 109 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-(OCH₂CH₂CH₂CO₂H)picolinic 1 4 4 32 16 16 acid 110 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-carboxypicolinic acid 0.125 4 NA 8 8 8 111 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-hydroxypicolinic acid 2 1 NA 2 2 64 112 4-Me-3-ClC₆H₃ 4-CH₃C₆H₄ 3-hydroxypicolinic acid 4 2 NA 4 8 64 113 4-Me-3-ClC₆H₃ Phenylethyl 3-hydroxypicolinic acid 0.5 1 NA 2 64 64 114 3-ClC₆H₄ 3-ClC₆H₄ 3-hydroxypicolinic acid 0.125 8 NA 64 64 16 115 4-EtO-3-ClC₆H₃ 4-EtO-3-ClC₆H₃ 3-hydroxypicolinic acid 2 2 1 8 16 64 116 2-Cl-5-Br-6- 2-F-4-ClC₆H₃ 3-hydroxypicolinic acid 2 1 0.25 4 4 64 FC₆H₂ 117 2-Me-4-ClC₆H₃ 3-ClC₆H₄ 3-hydroxypicolinic acid 2 1 0.5 4 4 16 118 2-Me-4-ClC₆H₃ 2-Me-4-ClC₆H₃ 3-hydroxypicolinic acid 1 0.25 0.12 1 1 16 119 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 3-OAc-picolinic acid 2 1 NA 2 2 64 120 4-Me-3-ClC₆H₃ 4-Me-3-ClC₆H₃ 4-hydroxybenzimidazole 0.125 4 NA 8 8 121 3-ClC₆H₄ 3-ClC₆H₄ 4-hydroxybenzimidazole 0.125 4 8 32 32 4 122 3-ClC₆H₄ 3-ClC₆H₄ 6-amino-3-hydroxypicolinic acid 0.25 4 16 32 32 8 123 3-ClC₆H₄ 3-ClC₆H₄ Imidazole acetic acid 0.125 2 8 32 32 8 Ceftriaxone 2 1 <0.125 64 64 0.12 Ciprofloxacin 0.12 0.12 0.5 0.5 64 0.12 Cloxacillin 0.12 0.25 0.12 16 64 8 Erythromycin 0.5 0.5 NA 2 NA 4 Imipenem 0.12 0.12 <0.125 1 64 2 Meropenem 0.06 0.06 NA 2 NA 0.06 Pen G 0.5 16 <0.125 1 32 0.12

TABLE 3 Anti-mycobacterium In vitro Activity M. tuberculosis MIC (mcg/mL) Compound H37Rv* P2SP1** P1SP2** 10 0.387 0.387 0.387 50 0.387 0.387 0.387 51 0.387 0.387 0.387 53 0.775 0.775 0.387 55 0.775 0.775 0.387 65 0.775 0.775 0.775 72 0.775 0.775 0.775 75 0.775 0.775 0.775 Isoniazid (INH) <0.062 >8 >8 Rifampicin <0.125 16 >16 Ethambutol <1 8 8 Ethionamide 1 >64 32 p-aminosalicylate <0.25 32 16 Ofioxacin 4 32 16 Streptomycin <2 <2 <2 Kanamycin <2 <2 <2 cycloserine 8 8 8 *Sensitive strain **Multi-drug resistant strain

The present invention also encompasses the acylated prodrugs of the compounds of the invention. Those skilled in the art will recognize various synthetic methodologies which may be employed to prepare non-toxic pharmaceutically acceptable addition salts and acylated prodrugs of the inventive compounds.

Tables 1 to 4 also contain inhibitory activity for known antibiotics, shown at the end of the tables.

EXAMPLES

Proton NMR are recorded on Varian AS 400 and MercuryPlus 300 MHz spectrometer and chemical shifts are reported as δ (ppm) down field from tetramethylsilane. Mass spectra are determined on Micromass Quattro II and Applied Biosystems AP3000. Compound numbers appear in parentheses and correspond to numbers in Tables 1 to 4.

Formation of Ethylene Glycol Boronate Ester (3, T=Nothing)

General Procedure TABLE 4 Antifungal Activity for Select Borinic Acid Complexes MIC (μg/ml) Candida Candida Aspergillus albicans glabrata Candida Microsporum fumigatus Trichophyton ATCC ATCC parapsilosis canis ATCC mentagrophytes Compound 90028 15126 ATCC 22019 ATCC 10214 204305 ATCC 10270  53 1 >32 32 16 >32 >32 124 1 >32 32 16 >32 >32 125 1 >32 32 16 >32 >32 126 1 >32 32 16 >32 >32 127 1 >32 16 16 >32 32 128 1 32 16 12 >32 16 129 1 >32 32 16 >32 32 130 1 0.5 0.5 0.5 0.5 0.5 131 2 >32 >32 32 >32 32 132 2 1 0.5 0.38 >32 0.25 Amphotericin B 1 0.75 0.75 0.5 1 1 Fluconazole 0.25 3 2.5 16 >64 16

Boronic acid was dissolved in dry THF, dry toluene or dry diethyl ether 110 mL/g) nitrogen. Ethylene glycol (1 molar equivalent) was added to the reaction and the reaction was heated to reflux for 1 to 4 hours. Reaction was cooled to room temperature and solvent was removed under reduced pressure leaving the ethylene glycol ester as an oil or a solid. In cases where an oil was obtained or a solid that dissolved in hexane, dry hexane was added and removed under reduced pressure. The product was then placed under high vacuum for several hours. In cases where a solid was obtained that did not dissolve in hexane, the solid was collected by filtration and washed with cold hexane.

3-Cyanophenylboronic acid ethylene glycol ester (3a)

3-Cyanophenyl boronic acid (1 g, 6.8 mmol) was dissolved in dry THF (10 mL) under nitrogen. Ethylene glycol (379 μL, 422 mg, 6.8 mmol) was added and the reaction was heated to reflux for 4 hours then cooled to room temperature. THF was removed by rotary evaporator to give a white solid. Cold hexane was added and the product was collected by filtration giving a white solid (1.18 g, quant. yield). ¹H-NMR (300.058 MHz, DMSO-d6) δ ppm 7.92-8.01 (3H, m), 7.50-7.64 (1H, m), 4.35 (4H, s)

Thiophene 3-boronic acid ethylene glycol ester (3b)

Thiophene-3-boronic acid (1 g, 7.8 mmol) was dissolved in dry THF (10 mL) under nitrogen. Ethylene glycol (435 μL, 484 mg, 7.8 mmol) was added and the reaction was heated to reflux for 1 hour then cooled to room temperature. THF was removed by rotary evaporator to give a white solid. Hexane was added, dissolving the solid and removed by rotary evaporation. The product was placed under high vacuum to yield a tan solid (1.17 g, 97%). ¹H-NMR (300.058 MHz, CDCl₃) δ ppm 7.93 (1H, s), 7.3-7.4 (2H, m), 4.35 (4H, s).

3-Fluorophenylboronic acid ethylene glycol ester (3c)

mixture of 3-fluorophenylboronic acid (7.00 g, 50.0 mmol) and ethylene glycol (2.8 mL, 50 mmol) in toluene (200 mL) was heated to reflux for 3 hours under Dean-Stark conditions. The solvent was removed under reduced pressure to afford 3-fluorophenylboronic acid ethylene glycol ester (7.57 g, 91%).

Formation of Unsymmetrical Borinic Acid (6) from Boronic Acid Ethylene Glycol Ester

General Procedure A: Grignard Methodology

Boronic acid ethylene glycol ester was dissolved in dry THF (10-20 mL/g) under nitrogen. Solution was cooled to −78° C. in an acetone/dry ice bath or to 0° C. in an ice/water bath. Grignard reagent (0.95 to 1.2 molar equivalent) was added dropwise to the cooled solution. The reaction was warmed to room temperature and stirred for 3-18 hours. 6N HCl (2 mL/g) was added and solvent was removed under reduced vacuum. Product was extracted into diethyl ether (40 mL/g) and washed with water (3× equal volume). Organic layer was dried (MgSO₄), filtered and the solvent was removed by rotary evaporation giving the crude product, which is either purified by column chromatography or taken onto the next step without purification. Alternative work-up: if the borinic acid product contained a basic group such as an amine or pyridine, then after stirring at room temperature for 3-18 hours, water (2 mL/g) was added and the pH adjusted to 5-8. Product was extracted into diethyl ether or ethyl acetate or THF up to three times (40 mL/g). Organic layer was dried (MgSO₄), filtered and the solvent was removed by rotary evaporation giving the crude product, which is either purified by column chromatography or taken onto the next step without purification.

(4-Cyanophenyl)(3-fluorophenylborinic acid (6a)

4-Cyanophenyl boronic acid ethylene glycol ester (500 mg, 2.89 mmol) was dissolved in dry THF under nitrogen. The solution was cooled to −78° C. in an acetone/dry ice bath and 3-fluorophenylmagnesium bromide (1M in THF)(2.74 mL, 2.74 mmol, 0.95 molar equivalent) was added dropwise to the cold solution. The reaction was allowed to warm slowly to room temperature and stirred for 18 hours. 6N HCl (1 mL) was added to the reaction causing a cloudy appearance and the solvent was removed using a rotary evaporator. The product was extracted into diethyl ether (20 mL) and washed with water (3×20 mL). The organic layer was dried (MgSO₄), filtered and the solvent removed using a rotary evaporator to yield the crude product as an oily solid. This was taken onto the next step without purification.

General Procedure B: (Hetero)Aryl-Lithium Methodology

The (hetero)aryl-bromide or iodide was dissolved in dry THF (20-30 mL/g) under nitrogen and degassed. The solution was cooled to −78° C. in an acetone/dry ice bath and n-, sec- or tert-butyllithium in THF or other solvent (1.2-2.4 molar equivalents) was added to the cooled solution dropwise (generally causing the solution to turn deep yellow). The boronic acid ethylene glycol ester (1 molar equivalent) was dissolved in dry THF or diethyl ether (2-10 mL/g) under nitrogen. The boronic acid ethylene glycol ester in THF was added dropwise to the cooled aryl-lithium solution (generally causing the solution to turn pale yellow). The reaction was warmed to room temperature and stirred for 1-18 hours. 6N HCl (2-4 mL/g) was added and solvent was removed under reduced vacuum. Product was extracted into diethyl ether (40 mL/g) and washed with water (3× equal volume). Organic layer was dried (MgSO₄), filtered and the solvent was removed by rotary evaporation giving the crude product, which is either purified by column chromatography or taken onto the next step without purification. Alternative work-up: if the borinic acid product contained a basic group such as an amine or pyridine then after stirring at room temperature for 3-18 hours water (2 mL/g) was added and the pH adjusted to 5-8. Product was extracted into diethyl ether or ethyl acetate or THF up to three times (40 mL/g) and washed with water (3× equal volume). Organic layer was dried (MgSO₄), filtered and the solvent was removed by rotary evaporation giving the crude product, which is either purified by column chromatography or taken onto the next step without purification.

(3-Thienyl)(3-chlorophenyl)borinic acid (6b)

3-Chloro-bromobenzene (447 μL, 728 mg, 3.8 mmol) was dissolved in dry THF (15 mL) under nitrogen. The solution was degassed and cooled to −78° C. in an acetone/dry ice bath. tert-Butyllithium (1.7M in THF)(4.47 mL, 7.6 mmol, 2 molar equivalent) was added to the cooled solution dropwise causing the solution to turn deep yellow. The solution was stirred at −78° C. while 3-thiopheneboronic acid ethylene glycol ester (586 mg) was dissolved in dry diethyl ether (1 mL). The boronic ester solution was then added dropwise to the cooled solution causing the color to change to pale yellow. The reaction was warmed to room temperature and stirred for 18 hours. 6N HCl (2 mL) was added and the reaction was stirred for 1 hour. The solvent was removed using a rotary evaporator. The product was extracted into diethyl ether (10 mL) and washed with water (2×10 mL). The organic layer was dried (MgSO₄), filtered and the solvent removed using a rotary evaporator to yield the crude product as an orange oil. The product was purified by column chromatography using silica gel and hexane:ethyl acetate 5:1 as eluent giving the pure product as a clear oil (614 mg, 73%).

(3-Chlorophenyl)vinylborinic acid (6c)

This was prepared by a similar process as described for 6b by the reaction of 3-cyanophenyl boronic acid ethylene glycol ester with vinyllithium.

(3-Fluoro-5-chlorophenyl)ethynlborinic acid (6d)

This was prepared by a similar process as described for 6b by the reaction of 3-fluoro-5-chlorophenyl boronic acid ethylene glycol ester with ethynyllithium.

(4-Methyl-3-chloro phenyl)(2-thienyl)borinic acid (6e)

This was prepared by a similar process as described for 6b by the reaction of 2-thienylboronic acid ethylene glycol ester with 4-methyl-3-chlorophenyllithium.

(4-Cyanophenyl)ethynylborinic acid (6f)

This was prepared by a similar process as described for 6b by the reaction of 4-cyanophenylboronic acid ethylene glycol ester with ethynyllithium.

(3-Fluorophenyl)cyclopropylborinic acid (6g)

This was prepared by a similar process as described for 6b by the reaction of 3-fluorophenylboronic acid ethylene glycol ester with cyclopropyllithium.

(3-Thienyl)methylborinic acid (6h)

This was prepared by a similar process as described for 6b by the reaction of 3-thienylboronic acid ethylene glycol ester with methyllithium.

(4-Pyridyl)phenylborinic acid (6i)

This was prepared by a similar process as described for 6b by the reaction of phenylboronic acid ethylene glycol ester with 4-pyridyllithium.

(3-Cyanophenyl)(2-fluorophenyl)borinic acid (6j)

This was prepared by a similar process as described for 6b by the reaction of 3-cyanophenylboronic acid ethylene glycol ester with 2-fluorophenyllithium.

4-(Dimethylaminomethyl)phenyl 3-fluorophenyl borinic acid (6k)

Sec-butyllithium (1.4 M in cyclohexane, 6.0 mL) was added to a solution of N,N-dimethyl-4-bromobenzylamine (1.50 g, 7.00 mmol) in THF (14 mL) at −78° C. under nitrogen atmosphere and the mixture was stirred for 15 min. 3-Fluorophenylboronic acid ethylene glycol ester (1.16 g, 7.00 mmol) in THF (7 mL) was added to the mixture. The reaction was allowed to warm to room temperature and stirred for 1 h. Water was added and the mixture was washed with ether. The pH was adjusted to 8 with 1M hydrochloric acid. The mixture was extracted with ethyl acetate twice. The organic layer was washed with brine and dried on anhydrous sodium sulfate. The solvent was removed under reduced pressure to afford the borinic acid (890 mg, 49%).

Formation of Symmetrical Borinic Acid (5) by Reaction of Organometallics with trialkyl borates. Bis(4-chlorophenyl)borinic acid (5a) (Procedure C)

A cold solution (−78° C.) of trimethyl borate (0.37 ml) in dry tetrahydrofuran (THF, 25 ml) was treated dropwise with 4-chlorophenylmagnesium bromide (6.75 ml, 1M solution in ether). The reaction mixture was stirred at −78° C. for 1 h and then stirred for 18 h at room temperature. The solvent was removed under reduced pressure. The resultant residue was stirred with 100 ml of ether and 15 ml of 6N hydrochloric acid. Organic layer was separated and aqueous layer was extracted with ether (2×100 ml). The combined organic extract was washed with brine and dried over anhydrous magnesium sulfate. Solvent was removed to give light yellowish solid. The product was chromatographed over silica gel (Hex: Ether=1:1) to give 420 mg of borinic acid. ¹H NMR (400 MHz, CDCl₃) δ: 5.84 (s, OH), 7.46 (d, 4H, Ar—H), 7.72 (d, 4H, Ar—H).

Bis(3-Chloro-4-methylphenyl)borinic acid (5b)

In a similar manner as for 5a, the titled compound was obtained from the reaction of 3-chloro-4-methylphenylmagnesium bromide with trimethyl borate. The product was obtained by chromatography over silica gel.

Bis(3-Fluoro-4-methylphenyl)borinic acid (5c)

In a similar manner as for 5a, the titled compound was obtained from the reaction of 3-fluoro-4-methylphenyllithium with trimethyl borate. The product was obtained by chromatography over silica gel.

Bis(3-Chloro-4-methoxyphenyl)borinic acid (5d)

In a similar manner as for 5a, the titled compound was obtained from the reaction of 3-chloro-4-methoxyphenyllithium with trimethyl borate. The product was obtained by chromatography over silica gel.

Bis(3-Fluoro-4-methoxyphenyl)borinic acid (5e)

In a similar manner as for 5a, the titled compound was obtained from the reaction of 3-fluoro-4-methoxyphenyllithium with trimethyl borate. The product was obtained by chromatography over silica gel.

Formation of Unsymmetrical Borinic Acids (6) by Reaction of Organometallics with alkyl(or aryl or alkenyl)dialkoxyboranes. (4-Chloro-phenyl)methyl-borinic acid (6m) (Procedure D)

To 4-chlorophenylmagnesium bromide (5.5 ml, 1M solution in ether) at −78° C., di(isopropoxy)methylborane (1 ml, 0.78 g) was added dropwise via syringe. The reaction mixture was stirred at −78° C. for 1 h and then stirred overnight at ambient temperature. The reaction mixture was treated dropwise with 100 ml of ether and 15 ml of 6N hydrochloric acid, and stirred for 1 h. Organic layer was separated and aqueous layer was extracted with ether (2×100 ml). The combined organic extract was washed with brine and dried over anhydrous sodium sulfate. Solvent was removed under reduce pressure to give 1.1 g of oil. ¹H NMR of the product was consistent for (4-chlorophenyl)methyl borinic acid.

(4-Fluorophenyl)methylborinic acid (6n)

In a similar manner as for 6m, the titled compound was obtained from the reaction of 4-fluorophenylmagnesium bromide with di(isopropoxy)methylborane. The product was obtained by chromatography over silica gel.

(4-Biphenyl)methylborinic acid (6o)

In a similar manner as for 6m, the titled compound was obtained from the reaction of 4-biphenyllithium with di(isopropoxy)methylborane. The product was obtained by chromatography over silica gel.

(3-Chloro-4-methylphenyl)methylborinic acid (6p)

In a similar manner as for 6m, the titled compound was obtained from the reaction of 3-chloro-4-methylphenyllithium with di(isopropoxy)methylborane. The product was obtained by chromatography over silica gel.

(3-Chloro-4-methoxyphenyl)methylborinic acid (6q)

In a similar manner as for 6m, the titled compound was obtained from the reaction of 3-chloro-4-methoxyphenyllithium with di(isopropoxy)methylborane. The product was obtained by chromatography over silica gel.

(4-Dimethylaminophenyl)methylborinic acid (6r)

In a similar manner as for 6m, the titled compound was obtained from the reaction of 4-dimethylaminophenyllithium with di(isopropoxy)methylborane. The product was obtained by chromatography over silica gel.

(3-Pyridyl)vinyl borinic acid (6s)

Isopropylmagnesium chloride (2.0 M in THF) (5.0 mL, 10 mmol) was added to a solution of 3-bromopyridine (1.60 g, 10.0 mmol) in THF (15 mL) under nitrogen atmosphere at room temperature and the mixture was stirred for 1 h. Vinylboronic acid dibutyl ester (3.4 mL) was added to the reaction dropwise and the mixture was stirred at room temperature for 18 h. Water was added and the pH was adjusted to 7 with 1 M hydrochloric acid. The mixture was extracted with ethyl acetate. The organic layer was washed with brine and dried on anhydrous sodium sulfate. The solvent was removed under reduced pressure to give the title compound (1.04 g, 78%).

(3-Chloro-4-dimethylaminophenyl)vinylborinic acid (6t)

In a similar manner as for 6s, the titled compound was obtained from the reaction of 3-chloro-4-dimethylaminophenyllithium with vinylboronic acid dibutyl ester. The product was obtained by chromatography over silica gel.

20

Borinic Acid-Alkylalcohol Derivatives

Bis(3-Chlorophenyl)borinic acid 4-(hydroxyethyl)imidazole ester (121)

To a solution of bis(3-chlorophenyl)borinic acid (0.4 g, 1.428 mmol) in ethanol (10 ml), 4-(hydroxyethyl)imidazole hydrochloride (0.191 g, 1.428 mmol), sodium bicarbonate (0.180 g, 2.143 mmol) were added and the reaction mixture was stirred at room temperature for 18 h. Salt was removed by filtration. Filtrate was concentrated and treated with hexane to afford the product as a solid and was collected by filtration. (450 mg, 84.9% yield). ¹H NMR (CD³OD) δ (ppm) 2.92 (t, 2H), 3.82 (t, 2H), 7.0-7.2 (m, 9H), 7.90 (s, 1H); (ES⁻)(m/z) 343.11, MF C₁₇H₁₅BCl₂N₂O

Bis(4-Chlorophenyl)borinic acid 4-(hydroxymethyl)imidazole ester (126)

In a similar manner as in Example 121, the titled compound was obtained from the reaction of bis(4-chlorophenyl)borinic acid with 4-(hydroxymethyl)imidazole hydrochloride. The product was obtained as white crystals. (ES⁻)(m/z) 328.79, MF C₁₆H₁₃BCl₂N₂O

Bis(3-Chloro-4-methylphenyl)borinic acid 1-benzyl-4-(hydroxymethyl)-imidazole ester (127)

To a solution of 1-benzyl-4-(hydroxymethyl)imidazole (96 mg, 0.521 mmol) in methanol (5 ml), bis(3-chloro-4-methylphenyl)borinic acid (121 mg, 0.521 mmol) was added and the reaction mixture was stirred at room temperature for 2 h. Solvent was removed under reduced pressure and the residue was treated with hexane to give a solid. The product was isolated by filtration and washed with hexane to give product (193 mg, 83%). ¹H NMR (CDCl₃) δ: 2.3 (s, 6H, 2XCH₃), 4.8 (brs, 2H, CH₂), 5.1 (brs, 2H, CH₂), 6.9-7.4 (complex, 13H, Ar—H); MS (ES⁻)(m/z) 448.78, MF C₂₅H₂₃BCl₂N₂O.

Bis(3-Chloro-4-methylphenyl)borinic acid 1-methyl-2-(hydroxymethyl)-imidazole ester (128)

In a similar manner as in Example 127, the titled compound was obtained from the reaction of bis(3-chloro-4-methylphenyl)borinic acid with 1-methyl-2-(hydroxy-methyl)imidazole hydrochloride. The product was obtained as white crystals. (ES⁺)(m/z) 372.82, MF C₁₉H₂₁BCl₂N₂O

Bis(3-Chloro-4-methylphenyl)borinic acid 1-ethyl-2-(hydroxymethyl)-imidazole ester (129)

In a similar manner as in Example 127, the titled compound was obtained from the reaction of bis(3-chloro-4-methylphenyl)borinic acid with 1-ethyl-2-(hydroxy-methyl)imidazole hydrochloride. The product was obtained as white crystals. (ES⁺)(m/z) 386.83, MF C₂₀H₂₃BCl₂N₂O

Bis(3-Chloro-4-methylphenyl)borinic acid 1-methyl-4-(hydroxymethyl)-imidazole ester (130)

In a similar manner as in Example 127, the titled compound was obtained from the reaction of bis(3-chloro-4-methylphenyl)borinic acid with 1-methyl-4-(hydroxy-methyl)imidazole hydrochloride. The product was obtained as white crystals. (ES⁺)(m/z) 372.88, MF C₁₉H₂₁BCI₂N₂O

Bis(3-Chloro-4-methylphenyl)borinic acid 2-pyridylethanol (131)

In a similar manner as in Example 121, the titled compound was obtained from the reaction of bis(3-chloro-4-methylphenyl)borinic acid with 2-pyridylethanol. The product was obtained as white crystals. (ES⁺)(m/z) 383.84, MF C₂₁H₂₀BCl₂NO

Hydroxyouinoline Derivatives

Bis(3-Chlorophenyl)borinic acid 5-cyano-8-hydroxycquinoline ester (19)

To a solution of bis(3-chlorophenyl)borinic acid (0.25 g) in ethanol (5 ml) and water (2 ml) was added 5-cyano-8-hydroxyquinoline (0.15 g). The solution was stirred at room temperature for 21 hours. A yellow solid precipitate formed which was collected by filtration and washed with cold ethanol. The product was obtained as yellow crystals. ¹H NMR (DMSO-d6) δ (ppm) 7.24-7.35 (m, 8H), 7.38 (d, 1H), 8.18 (dd, 1H), 8.40 (d, 1H), 8.86 (d, 1H), 9.50 (d, 1H).

(3-Chlorophenyl)(2-thienyl)borinic acid 8-hydroxyquinoline ester (36)

To a solution of (3-chlorophenyl)(2-thienyl)borinic acid (1.5 g) in ethanol (2 ml) was added 8-hydroxyquinoline (0.77 g) in hot ethanol (2 ml). The reaction was heated to reflux and cooled to room temperature. A yellow solid precipitated. The mixture was cooled in ice, the solid was collected by filtration and washed with cold ethanol. The product was obtained as a yellow solid (1.01 g). ¹H NMR (DMSO) δ (ppm) 6.98-7.06 (m, 2H), 7.19-7.26 (m, 3H), 7.38-7.50 (m, 4H), 7.71 (t, 1H), 7.91 (dd, 1H), 8.80 (d, 1H), 9.18 (d, 1H); (ESI⁺)(m/z) 350.1, MF C₁₉H₁₃BCINOS

(2-Thienyl)methylborinic acid 8-hydroxycquinoline ester (26)

In a similar manner as in Example 36, the titled compound was obtained from the reaction of (2-thienyl)methylborinic acid with 8-hydroxyquinoline. The product was obtained as yellow crystals.

(3-Cyanophenyl)vinylborinic acid 8-hydroxycquinoline ester (40)

In a similar manner as in Example 36, the titled compound was obtained from the reaction of (3-cyanophenyl)vinylborinic acid with 8-hydroxyquinoline. The product was obtained as yellow crystals. (ESI⁺)(m/z) 285.1, MF C₁₈H₁₃BN₂O

(2-Chlorophenyl)ethynylborinic acid 8-Hydroxyquinoline ester (43)

In a similar manner as in Example 36, the titled compound was obtained from the reaction of (2-chlorophenyl)ethynylborinic acid with 8-hydroxyquinoline. The product was obtained as yellow crystals. (ESI⁺)(m/z) 292.1, MF C₁₇H₁₁BCINO

Bis(ethynyl)borinic acid 8-Hydroxyquinoline (44)

In a similar manner as in Example 36, the titled compound was obtained from the reaction of bis(ethynyl)borinic acid with 8-hydroxyquinoline. The product was obtained as light yellow crystals. (ESI⁺)(m/z) 206. 1, MF C₁₃H₈BNO

(3-Fluorophenyl)cyclopropylborinic acid 8-hydroxyquinoline ester (70)

In a similar manner as in Example 36, the titled compound was obtained from the reaction of (3-fluorophenyl)cyclopropylborinic acid with 8-hydroxyquinoline. The product was obtained as light yellow crystals. (ES⁻)(m/z) 291.05, MF C₁₈H₁₅BFNO

(3-Pyridvl)vinylborinic acid 8-hydroxyquinoline ester (99)

A solution of (3-pyridyl)vinyl borinic acid (1.04 g, 7.82 mmol) and 8-hydroxyquinoline (961 mg, 6.63 mmol) in ethanol was stirred at 40° C. for 20 min. The solvent was removed under reduced pressure and the residue was crystallized from diethyl ether/diisopropyl ether/hexane to afford the title product (99) as a light yellow powder (355 mg, 21%). ¹H NMR (DMSO-d₆) δ (ppm) 5.23 (dd, 1H), 5.46 (dd, 1H), 6.43 (dd, 1H), 7.14 (d, 1H), 7.19 (dd, 1H), 7.41 (d, 1H), 7.6-7.8 (m, 2H), 7.88 (dd, 1H), 8.35 (dd, 1H), 8.57 (s, 1H), 8.76 (d, 1H), 9.00 (d, 1H); ESI⁺ (m/z) 261 MF C₁₆H₁₃BN₂O.

(4-(Dimethylaminomethyl)phenyl)(3-fluorophenyl)borinic acid 8-hydroxy-quinoline ester (100)

In a similar manner as in Example 99, the titled compound was obtained from the reaction of (4-(Dimethylaminomethyl)phenyl)(3-fluorophenyl)borinic acid with 8-hydroxyquinoline. The product was obtained as a light yellow powder. ESI⁺ (m/z) 385 MF C₂₄H₂₂BFN₂O.

3-Hydroxypicolinic Acid Derivatives

Bis(3-Chloro-4-methylphenyl)borinic acid 3-hydroxypicolinate ester (111)

Bis(3-chloro-4-methylphenyl)borinic acid (14.6 g) was dissolved in ethanol (120 ml) and heated to reflux. 3-Hydroxypicolinic acid (5.83 g) was added in portions to the hot solution. The reaction was stirred at reflux for 15 minutes after the addition of the last portion of 3-hydroxypicolinic acid was added and then cooled to room temperature. Reaction was concentrated by removal of some ethanol. Solid was removed by filtration. One recrystallization from ethanol afforded the title product as white crystals (13.4 g). MP=165.0-166.5° C.

In a preferred embodiment, the present invention includes the compounds specifically recited herein, and pharmaceutically acceptable salts thereof, and compositions of any of these compounds where these comprise a pharmaceutically acceptable carrier.

The present invention also relates to a method for treating a microbial-caused disease in a patient afflicted therewith and/or preventing such infection in a patient at risk of becoming so-infected, comprising administering to said patient a therapeutically effective amount of any of the compounds of the invention, preferably one or more of those listed in Tables 1 to 4. In one aspect, the compounds of the invention have anti-bacterial (i.e., bactericidal) and anti-fungal (i.e., fungicidal) activity.

In a preferred embodiment, the microbe is a bacterium, preferably a gram positive bacterium, wherein said gram positive bacterium is a member selected from the group consisting of Staphylococcus species, Streptococcus species, Bacillus species, Mycobacterium species, Corynebacterium species, Clostridium species, Actinomyces species, Enterococcus species, and Streptomyces species.

In another preferred embodiment of such method, the bacterium is a gram negative bacterium, preferably one selected from the group consisting of Acinetobacter species, Neisseria species, Pseudomonas species, Brucella species, Agrobacterium species, Bordetella species, Escherichia species, Shigella species, Yersinia species, Salmonella species, Klebsiella species, Enterobacter species, Haemophilus species, Pasteurella species, Streptobacillus species, spirochetal species, Campylobacter species, Vibrio species, and Helicobacter species.

In a highly preferred embodiment of the present invention, the bacterium is a member selected from the group consisting of Staphylococcus aureus; Staphylococcus epidermidis; Staphylococcus saprophyticus; Streptococcus pyogenes; Streptococcus agalactiae; Streptococcus pneumoniae; Enterococcus faecalis; Enterococcus faecium; Bacillus anthracis; Mycobacterium avium; Mycobacterium tuberculosis; Acinetobacter baumanii; Corynebacterium diphtheria; Clostridium perfringens; Clostridium botulinum; Clostridium tetani; Neisseria gonorrhoeae; Neisseria meningitidis; Pseudomonas aeruginosa; Legionella pneumophila; Escherichia coli; Yersinia pestis; Haemophilus influenzae; Helicobacter pylori; Campylobacter fetus; Campylobacter jejuni; Vibrio cholerae; Vibrio parahemolyticus; Trepomena pallidum; Actinomyces israelii; Rickettsia prowazekii; Rickettsia rickettsii; Chlamydia trachomatis; Chlamydia psittaci; Brucella abortus; Agrobacterium tumefaciens; and Francisella tularensis.

In a preferred embodiment the microbe is a fungus or yeast wherein said fungus is a member selected from the group consisting of Aspergillus species, Trichophyton species, Microsporium species, Cryptococcus neoformans, Blastomyces dermatitidis, Coccidiodes immitis, Histoplasma capsulatum, or Paracoccidioides brasiliensis and wherein said yeast is a member selected from the group consisting of Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, or Candida parapsilosis. 

1-80. (canceled)
 81. A compound described herein.
 82. A method for treating a microbial-caused disease in a patient afflicted therewith comprising administering to said patient a therapeutically effective amount of a compound described herein.
 83. A method for killing a microorganism or inhibiting the growth of a microorganism, comprising contacting said microorganism with an amount of a compound described herein. 